Reversible hydraulic driving mechanism



Nov. 28, 1933. 1,937,077

REVERSIBLE HYDRAULIC DRIVING MECHANISM Filed March 3, 1931 v 4Sheets-Sheet l ,ZOIZO'JQZ W563 Nov. 28, 1933. D. H. WEST v 1, ,0

REVERSIBLE HYDRAULIC DRIVING MECHANISM Filed March 3, 1931 4Sheets-Sheet 2 6, was?? Nov. 28, 1933. D. H. WEST 1,937,077

REVERSIBLE HYDRAULIC DRIVING MECHANISM Filed March 5, 1951 4Sheets-Sheet 3 30 .Q 12- if V -77 J]! Lu :1; 5.4

;m% M2 21 7 J05 v14 i-% r e 1 D. H. WEST 1,937,077

Nov. 28, 1933.

REVERSIBLE HYDRAULIC DRIVING MECHANISM 4 Sheets-Sheet 4 Filed March 5,1931 70 c Q T 60 jndrza Jor/aZ ZZi' W642 Patented- Nov. 28, 1933 UNITEDSTATES PATENT OFFICE REVERSIBLE HYDRAULIC DRIVING MECHANISM ApplicationMarch 3, 1931. Serial No. 519,750

g 6 Claims.

This invention relates to mechanism for driving machines, such as sheetsteel rolling mills, which are operated alternately in oppositedirections.

It is the general object of my invention to pro- 5 vide improvedhydraulic mechanism for eifectively driving such alternately operatedmachines.

My invention further relates more specifically t the provision ofhydraulic driving mechanism adapted to simultaneously exert a definitedriving or pulling force with one portion of the apparatus and to exerta definite retarding force with another portion of the apparatus. Thesetwo portions of the apparatus are commonly connected to the oppositeends of the piece of material which is being rolled or otherwiseoperated on by the driven apparatus.

I also provide means for reversing the direction of operation of thehydraulic mechanism, for regulating the driving speed, and for variablydeter- 20 mining the retarding force.

My invention further relates to arrangements and combinations of partswhich will be hereinafter described and more particularly pointed out inthe appended claims.

A preferred form of the invention is shown in the drawings, in whichFig. 1 is diagrammatic perspective view showing the general arrangementof my improved hydraulic driving mechanism;

Fig. 2 is a sectional side elevation of the pump used in my improveddriving mechanism;

Fig. 3 is a transverse sectional elevation, taken along the line 3--3 inFig. 2;

Fig. 4 is a partial sectionalplan view, taken along the line 44 in Fig.3;

Fig. 5 is a sectional side elevation of certain valve mechanism to bedescribed;

Fig. 6 is a detail sectional end elevation, taken along the line 6--6 inFig. 5:

Fig. '7 is a detail sectional elevation showing certain parts of Fig. 5in a diiferent position;

Fig. 8 is a sectional side elevation of one of the hydraulic motors. andI Fig. 9 is a partial sectional plan view, taken along the line 9-9 inFig. 8.

I will first describe the general features and method of operation of myinvention, and I will thereafter describe the detail construction ofcertain mechanisms used therein.

In Fig. 1 I have shown my invention as applied to the rolling of sheetsteel or other similar ma.- terial. The rolling mechanism is indicateddiagrammatically as comprising sheet-engaging or die rolls 1010 andpressure rolls 11--11. The stock S is guided to and from the die rolls10 by guide rolls 12, and the ends of the stock S are secured to drums14 and 15 mounted on driving shafts 16 and 17 which are directlyconnected to the rotors of a pair of hydraulic motors A and B.

The motors A and B are connected by pipes 20 B0 and 21 to the casing ofa control valve mechanism,

V and are also connected by pipes 22 and 23 to a return pipe 24 whichdischarges into a storage tank T. The casing of the control valvemechanism V is connected by a pipe 25 to a hydraulic pump P, which ispreferably driven by a directconnected motor M. A supply pipe 26 leadsfrom the tank T to the pump P.

An adjustable needle valve mechanism N is connected by a pipe 27 to thecontrol valve mechanism V and by a pipe 28 to the tank T. A piston valvein the valve mechanism V is connected to a valve rod 30, extendingthrough the head of the valve casing and connected to one end of a lever31, pivoted at 32 and having its upper end slotted at 33 to receive astud 34 on a bar 35 mounted to slide in fixed bearings 36.

At its opposite ends, the bar 35 is provided with depending'inclined camportions 3'? and 38. These cam portions are positioned for engagement bylugs 39 and 40, formed on or secured to the edge of the strip of stock Sand near the ends thereof.

The general operation of the device is as follows: The motor Mpreferably revolves at constant speed and drives the rotor of the pumpP. This pump is preferably of the positively-acting, variable-delivertype and the rate of delivery may be adjus, by means of a hand wheel 42or in any other convenient manner.

The oil, water or other transmission liquid in the tank T is drawnupward through the supply pipe 26 to the pump P and is delivered by thepump P through the pipe 25 to the valve mechanism V. This valvemechanism will be hereinafter described but for present purposes it maybe stated that the piston valve is adjustable to connect the pumpdelivery pipe 25' to either of the pipes 20 or 21 leading to the motorsA and B respectively.

When one of these pipes 20 or 21 is connected .to the pipe 25, the otherpipe 20 or 21 will be connected through the pipe 2'7, needle valvemechanism N and pipe 28 to the storage tank T.

Assuming that the piston valve in the control mechanism V is set inposition to connect the pump discharge pipe 25 to the motor connection20, the hydraulic motor A will be operated to turn the drum 14 clockwiseor in the direction of-the arrow as and to draw the strip S through thedie rolls 10 and to wind the same on the roll 14. The 110 discharge fromthe motor A will flow through the pipes 22 and 24 to the. storage tankT.

At the same time, the drum 15 will beturned in the direction of thearrow y by the pull of the stock S, thus positively rotating thehydraulic motor B in a backward or unwinding direction, causing themotor to draw in oil from the tank T through the pipes 24 and 23 and todischarge the oil through the pipes 21 and 27, needle valve mechanism Nand pipe 28 back to the tank T.

By adjusting the needle valve mechanism N, the resistance to the flow ofoil through this circuit may be increased or decreased as desired, andconsequently any desired retarding force may be exerted on the strip Sas it is unwound from the drum 15.

When a short length only of the strip S remains on the drum 15. theprojection 40 on the edge of the strip engages the cam portion 38,sliding the bar 35 to the left, and reversing the position of the pistonvalve in the control valve mechanism V. The motor B will then operate asa motor to draw the stock S through the die rolls 10 in the oppositedirection, and the motor A will exert a braking or retarding effect onthe stock S as it is unwound from the drum 14.

It is found that this retarding effect is extremely important and thatby varying the retarding action the density and structure of the metalbeing rolled may be substantially varied and controlled.

It is obvious that the direction of motion and point of reversal may becontrolled by shifting the lever 31 manually as well as automatically.Furthermore, the automatic reversing mechanism is illustrative only andany other suitable reversing devices may be substituted therefor.

Having described the general construction and operation of my improvedhydraulic driving mechanism I will now describe certain details of theoperating mechanism.

In Figs. 2, 3 and 4 I have illustrated the construction of a preferredform of positively-acting, variable-delivery pump P. In this type ofpump, a rotor 50 is mounted on a motor-driven shaft 51 and is providedwith an annular series of cylinders 52, connected through passages 53and ports 54 to a series of openings 55 spaced about a fixed bearingmember 56 which has passages 57 connected to the intake or suction pipe26 and additional passages 58 connected to the discharge pipe 25previously described.

The pistons 60 are movable in the cylinders 52 along lines parallel tothe axis of the rotor 50 and driving shaft 51. These pistons 60 areconnected by piston rods 61 and swivel joints 62 to a socket plate 63,which is positively rotated through aswi-vel connection 64 by the driveshaft 51, in unison with the rotation of the rotor 50.

The socket plate 63 is mounted in bearings in a cradle block or casing65, which in turn ismounted in transverse bearings in the casing 66 ofthe pump P, the axis of these transverse bearings intersecting the axisof the shaft 51 and rotor 50 at the point Z (Fig. 2).

The cradle block of casing 65 is preferably provided with segment gearteeth 68 centered about the point Z and engaged by a pinion 6'7,connected to the hand wheel 42 previously described. By turning the handwheel, the angular setting of the cradle block or casing 65 may beadjusted as desired. The greater the angle, the higher the rate ofdischarge of thepump for a given speed.

For a more detailed description of the pump reversible action.Obviously, adjustment of the socket plate 71 to a position nearlyperpendicular to the axis of the motor shaft would introduce suchresistance that it could not be overcome by any available pressure inthe cylinders of the rotor, and consequently the apparatus would beinoperative as a retarding motor but would merely lock the unwindingdrum. At an angle of approximately fifteen degrees, as shown in Fig. 8,the rotor is found to operate at its greatest emciency and to besatisfactorily reversible.

The details of the contol valve mechanism V are clearly shown in Figs.5, 6 and 7. The valve mechanism V comprises a casing 80 having acylindrical opening 81 with a plurality of enlarged annular portopenings 82, 83, 84, and 86.

The pump delivery pipe 25 is connected to the middle port 84 (Fig. 6).The supply pipes 20 and 21 for the motors A and B are connected to theports 85 and 83 (Fig. 5) respectively. The end ports 82 and 86 areconnected to a common passage 8'7, which in turn is connected to thepipe 27 leading to the needle valve mechanism N.

The piston valve comprises cylindrical portions 90, 91, 92 and 93 andreduced connecting portions 94, the entire valve being connected as aunit to the valve rod 30 previously described.

In Fig. 5 I have shown the piston valve in its middle or neutralposition, but in Fig. '7 the piston nism comprises a casing having acylindrical opening 101 in which a piston valve 102 is axiallyadjustable. The cylindrical opening 101 is provided with annular portopenings 103 and 104, the first being connected to the pipe 27 and thesecond to the pipe 28.

The piston valve 102 comprises cylindrical portions 105 and 106connected by a tapered or conical portion 107. The piston valve may beadjusted axially by a hand wheel 110 mounted on the end of the pistonrod 111, which is threaded into a fixed projection 112. By adjusting theconical portion 105 axially with respect to the port opening 104, theeffective area of the port or passage between the pipes 2'7 and 28 maybe restricted as desired, and consequently the retarding effect of themotor A or B as rotated by the unwinding of the stock S may be readilyadjusted to operating conditions. 7

I have now described the general construction and operation of myimproved hydraulic driving mechanism and the details of such parts ofthe mechanism as are necessary for the purposes of understanding thisinvention.

It will be seen that I have provided extremely simple mechanismcomprising a variable-discharge, motor-driven pump P and a pair ofreversible hydraulic motors A and B, together with suitable controlmechanism by which the motors A and B and winding drums 14 and 15 may bealternately rotated in opposite directions, and by which the idlehydraulic motor may be utilized as a brake or drag, with the braking orretarding effect readily adjustable. The mechanism is thus extremelywell adapted for driving a rolling mill or any other apparatus in whichthe direction of operation is frequently reversed, and particularlyapparatus in which a drag or braking effect is desired.

Having thus described my invention and the advantages thereof, I do notwish to be limited to the details herein disclosed, otherwisethan as setforth in the claims, but what I claim is:-

1. Reversible driving mechanism comprising a pump, a pair of hydraulicmotors, and a control valve mechanism effective to connect either motorto said pump and to a fluid storage, and the other motor to said fluidstorage and to a higher pressure fluid discharge.

2. Reversible driving mechanism comprising a pump, a pair of hydraulicmotors, and a control valve mechanism effective to connect either motorto said pump and to a fluid storage, and the other motor to a lowpressure fluid supply and to a higher pressure fluid discharge, saiddischarge including an adjustable flow-restricting valve.

3. In a machine for acting on an elongated piece of flexible material, apair of hydraulic motors each adapted to either pull or retard saidmaterial, means to supply fluid under relatively high pressure to drivea selected motor to pull said piece of material through said machine,said material being attached to and turning the second motor as thematerial is unwound, connections supplying fluid at low pressure to saidsecond motor, means to oppose discharge thereof at a higher pressure,and selective means to connect said higher pressure fluid supplyingmeans to one motor and said connections and discharge opposing means tothe other motor interchangeably and alternately, whereby the operationof the machine is reversed.

4. In a machine for acting on an elongated piece of flexible material, apair of hydraulic mo-' tors each adapted toeither pull or retard saidmaterial having winding drums for said material, means to supply fluidunder relatively high pressure to .drive a selected motor to turn theassociated winding drum and pull said material through said machine,said material being attached to the second winding drum and turning thesecond motor as the material is unwound from said second drum,connections supplying fluid at low pressure to said second motor, meansto oppose discharge thereof at a higher pressure, and selective means toconnect said high pressure fluid supplying means to one motor and saidconnections anddischarge opposing means-to the other motorinterchangeably and alternately, whereby the operation of the machine isreversed.

5. In a -machine for acting on an elongated piece of flexible material,a pair of hydraulic motors each adapted to either pull or retard saidmaterial, means to supply fluid under relatively high pressure to drivea selected motor to pull said piece of material through said machine,said material being attached to and turning the second motor as thematerial is unwound, connections supplying fluid at low pressure to saidsecond motor, means to oppose discharge thereof at a higher pressure,and means to simultaneously reverse the operation of said two motors.

6. In a machine for acting on an elongated piece of flexible material, apair of hydraulic motors each adapted to either pull or retard saidmaterial, means to supply fluid under relatively high pressure to drivea selected motor to pull said piece of material through said machine,said material being attached to and turning the second motor as thematerial is unwound, connections supplying fluid at low pressure to saidsecond motor, means to oppose discharge thereof at a higher pressure,and means to simultaneously reverse the operation and direction ofrotation of said two motors. I

DONALD-H. WEST.

